Funny thing, going solo. Seems to be a matter of degree.
I didn't count, but my impression is that there are about the same number of folks going solo as with groups. Even some of the groups were very loose associations of individuals spending much of the time solo on the trail, miles separating them from the rest of their group, and maybe camping together at night, maybe not. On the other hand, I rean across a couple of solos who joined up during the hike. A very few groups were very tight, always in direct contact, conversing as they hiked, but these were the minority. And even among the tightest groups, I saw almost no one except couples sharing tents, cooking, stoves etc.
I think this is the biggest cultural difference I noticed on this trip (August JMT solo) from when I began hiking at camp, in Scouts, with family, etc. a hundred or so years ago. When I took my family on the HST two years ago, I packed all meals for 5, took a big pot/cookset and we all ate family style, siblings shared tents, etc. Probably a vestige of when gear was much heavier, and there was a real economy in packing only one stove for five people, tents for 2-4 etc. Now everything is so light even the less efficient way of doing things is far lighter than the most efficient way years ago, and we can afford the luxury of more privacy, individual choice about meals, etc.
In the old style, if 8 or ten people were sitting around the fire at dinner time chances are one big pot was on the fire, and someone designated camp cook was doling out portions into Sierra cups all around. On this trip, when there were 10 or 12 of us sitting in a circle at the Tyndall Frog ponds, there were 10 or 12 stoves, 10 or 12 different concoctions brewing in 10 or 12 different titanium pans, Jet-Boils, mylar pouches, Sigg pots (me) or even just cold-mixed in ziploc bags.
Different strokes.